1. S. Banach, Théorie des opérations linéaires, Monografje Matematyczne, Warsaw, 1932.
2. Orthogonality in linear metric spaces;Birkhoff, Garrett;Duke Math. J.,1935
3. Extensions of functionals on complex linear spaces;Bohnenblust, H. F.;Bull. Amer. Math. Soc.,1938
4. Uniformly convex spaces;Clarkson, James A.;Trans. Amer. Math. Soc.,1936
5. Polygons circumscribed about closed convex curves;Day, Mahlon M.;Trans. Amer. Math. Soc.,1947